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820-3476-a missing s4 rails.

B

BCN_Techs

Member
Hi guys,

Other motherboard with same s4 missing.

HEre are my measurements.


ppbus_g3h - 12,6V
PPBUS_S5_HS_COMPUTING 12,6V
PPBUS_S5_HS_OTHER5V 12,6V
PPBUS_S5_HS_OTHER3V3 12,,6V
PPDCIN_G3H 20V
PP3V42_G3H 3,45V
PPVRTC_G3H 3,3V

PP5V_S5 5V
PP5V_S4 0V, not shorted to ground Diode mode: 0,404 Resistnce to ground: 1,2 mhoms
PP3V3_S5 3,3V
PP3V3_S4 0V not shorted to ground Diode mode: 0,380 Resistance to roud 0,5mhoms

PP3V3_SUS 0V, not shorted Diode mode 0,342

ppbus_g3h - 12,6V
PPBUS_S5_HS_COMPUTING 12,6V
PPBUS_S5_HS_OTHER5V 12,6V
PPBUS_S5_HS_OTHER3V3 12,,6V
PPDCIN_G3H 20V
PP3V42_G3H 3,45V
PPVRTC_G3H 3,3V

PP5V_S5 5V
PP5V_S4 0V, not shorted to ground Diode mode: 0,404 Resistnce to ground: 1,2 mhoms
PP3V3_S5 3,3V
PP3V3_S4 0V not shorted to ground Diode mode: 0,380 Resistance to roud 0,5mhoms

PP3V3_SUS 0V, not shorted Diode mode 0,342

PM_SLP_S5_L missing


Seems something usual for theese board to miss s4 reails.

No water damge.


Seems something usual for theese board to miss s4 reails.

No water damge.
 
2informaticos

2informaticos

Administrator
Staff member
"PP3V3_SUS 0V"
Also missing PM_SLP_SUS_L?

Post SMC_ADAPTER_EN, PM_BATLOW_L, S5_PWRGD, PM_DSW_PWRGD, PCH_DSWVRMEN and the 4 RTC signals.
Check if U1900 sends out 32KHz oscillation and PPVRTC_G3H.

Charging battery, magsafe light?
 
B

BCN_Techs

Member
SMC_ADAPTER_EN 3.3V
PM_BATLOW_L 3.4V
PM_DSW_PWRGD 3.4V
PCH_DSWVRMEN 3.2V

Unfortunatly i dont have o-scope here..


For 4 rtc signals what u mean?
 
2informaticos

2informaticos

Administrator
Staff member
"For 4 rtc signals what u mean?"
U0500, page 12 (SYM 5 of 19).

"Unfortunatly i dont have o-scope here.."
Post DC value at least.
If you plan to stay in this business, get a cheap analog o-scope; should be good enough.

"Also missing PM_SLP_SUS_L?"
???
 
B

BCN_Techs

Member
PM_SLP_SUS_L is missing, 0V

RTC_RESET_L 3.3V
PCH_INTRVRMEN - 3.2V
PCH_INTRUDER_L - 3V
PCH_SRTCRST_L - 3.3 V

U1900 Pin 4 0,1V.

WIll buy o-scope next week.
 
2informaticos

2informaticos

Administrator
Staff member
U1900 pin12; usually 0.45V DC when oscillation present.
However this will not confirm 100% good oscillation...

Your issue seems to be PCH related, as it doesn't release SLP_SUS.
Try to reflow it till 200 degrees.
 
2informaticos

2informaticos

Administrator
Staff member
If all previous measurements are correct, PCH is bad.
Remember, there still exists a doubt about 32KHz for RTC block...
You can change U1900, just in case.
 
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